Envelop.



UNITED STATES PATENT OFFICE.

EiWELoP.

Specification of Letters Patent.

Patented Dec. 10, 1907.

Application filed March 30.1907. Serial No. 365-617- To all whom it may concern:

Be it known that I, BENJAMIN DAVIS, a citizen of the United States, residing at N escs uehoning, in the county of Carbon and tate of Pennsylvania, have invented certain new and useful Improvements in Envelops, of which the following is a specification.

This invention relates to envelops.

The object of the invention is to provide an exceedingly simple, inexpensive, durable and efiioient envelop embodying such characteristics that it cannot be opened without detection.

With the above and other objects in view, the present invention consists in the combination and arrangements of parts hereinafter more fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that changes may be made in the form, proportion, size and minor details without departing from the spirit or sacrificing any ofthe advantages of the invention.

In the drawings:Figure 1 is a plan view of the blank from which my improved envelop is formed. Fig. 2 is a view of the back of the envelop in its sealed condition. Fig. 3 is a transverse sectional view.

Referring now more particularly to the accompanying drawings, the reference character 1 indicates the front or address side of the envelop provided at its ends with the end flaps 2 and 3 designed to be folded over on the front or address side of the envelop with their meeting edges overlapping and sealed by any suitable adhesive substance.

The reference character 4 indicates the back flap of the envelop designed to overlap the end flaps and be sealed thereto along its edges in the usual manner. This back flap is provided with a slot 5 having a recess 6 along its lower edge to facilitate the insertion through the slot of the tapering, elongated, intermediate tongue 7 of the closure flap 8,

there being short end tongues 9 upon opposite sides of the intermediate flap 7 for sealing engagement with the exterior of the back flap at the ends of said slot 5. mediate flap 7 does not have sealing engagement with the inner face of the back flap 4,

but it does have sealing engagement with the outer face of the overlapping end flaps 2 and 3.

From the foregoing it will be understood that the tongues have adhesive substance upon their inner faces andthat the intermediate tongue passes through the slot 5 for sealing engagement with a part of the envelop within the back of the latter, while the end tongues 9 have sealing engagement with the outer face of the back flap 9 at the ends of the slot. Of course, the edge of the sealing flap is provided with the usual adhesive .substance.

I claim for my invention that in the event of an unauthorized person attempting to unseal the same the envelop would be torn, and by reason of the intermediate tongue 7 passing through the slot 5, a steaming operation of the envelop will not eifect an unsealing of the envelop, as is the manner frequently accomplished in the use of an ordinary envelop when placed over steam.

What is claimed is An envelop comprising overlapping end flaps, a back flap overlapping the end flaps and provided with a slot having a recess in its under edge intermediate the ends of the slot, the upper edge of the slot being straight, and a closure flap having three alining tongues, the intermediate tongue being considerably longer than the end tongues and formed for insertion through said slot for sealing engagement with the backs of the end flaps, and the end tongues being arranged for sealing engagement with the outer face of the back flap only at opposite ends of said slot. In testimony whereof I affix my signature, in presence of two wintesses.

BENJAMIN DAVIS.

Witnesses DAVID TREVOSSON, OHAs. MARSDEN.

The inter- 

